Just wanted to say thank you for all the lovely messages. The news has sneaked out a little earlier than we had hoped but Ali and I are delighted to be expecting our first child. Thanks for all the love, we really appreciate it ❤️ D x pic.twitter.com/g7mZrWLYs4

Astall, who was Ant and Dec’s manager for more than a decade, married Donnelly in August 2015, with McPartlin acting as their best man.

The couple thanked fans for their messages of support after the pregnancy was revealed, saying: “Thanks for all the love, we really appreciate it D x.”

Meanwhile, the details of the first ever episode of Saturday Night Takeaway without Ant McPartlin have been revealed.

Stephen Merchant will be the star guest announcer, while musical guests include The Script and Paloma Faith.

In a statement regarding the remaining episodes of Takeaway, ITV said: “ITV can confirm that Saturday Night Takeaway, presented by Declan Donnelly, will return on March 31, and the series finale will be taking place at Universal Orlando Resort in Florida a week later.”

Meanwhile Dec posted a message about taking the stage without his life-long presenting partner.

“Whilst I never thought I’d be in this position, after much discussion and careful consideration we’ve decided that the remaining two shows of this series of Saturday Night Takeaway will go ahead,” he said.

“We made a promise to take hundreds of deserving winners to Florida to watch the series finale, and we will honour that. Everyone at ITV and the Takeaway team feels we owe it to the audience to complete the series.”